Chromatographic Effects in Inkjet Printing

Abstract

We have studied the chromatographic separation of solvents and dyes after deposition of a dye solution on a paper substrate. Due to their larger molecular size, dyes typically exhibit a stronger interaction with the paper constituents. Consequently, the imbibition process of the dye is usually delayed compared to that of the solvent. This impacts the achievable resolution and color homogeneity in inkjet printing. We present experiments and a comprehensive numerical model to illustrate and quantify these effects. The model accounts for the solvent evaporation, heat transfer, multicomponent unsaturated flow, and dye adsorption, as well as the presence of permeable fibers in the paper substrate. We identify the key parameters that can be tuned to optimize the pattern fidelity of the printing process.

Transport and evaporation of aqueous co-solvent solutions in thin porous media

“…At 𝑐 0 = 20 wt%, a brighter center region can be seen. This phenomenon is observed reproducibly and possibly due to chromatographic retention [48]. The cross-sectional profiles 𝛥𝐼(𝑥)∕𝐼 0 for the different concentrations are plotted in Fig.…”

A Numerical Model for the Transport and Drying of Solutions in Thin Porous Media -- Coffee-Stain Effect and Solute Ring Formation

“…For the transport of co-solvent solutions, adsorption effects are usually weak, because the adsorption capacity is much smaller than the deposited co-solvent content. In contrast, for the transport of dilute solutions, adsorption is a strong effect, contributing to chromatographic retention [5].…”

Transient deformation and swelling of paper by aqueous co-solvent solutions

“…4 In the field of inkjet printing, inks are often based on water as an environmentally friendly main solvent. 5,6 Besides colorants and surfactants, 7,8 they commonly contain so-called co-solvents -polar liquids such as glycerol or glycolswith a concentration up to 50 wt%. 5 Their primary purpose is to serve as humectants for preventing inkjet nozzle clogging, but also as anti-cockle and anti-curl agents.…”